This is just about the time banking became a thing in Italy. Most(?) humans would still be in pre-history. Maybe you could detect increased activity along the silk-road if you look closely.

Pollution levels in the atmosphere would still be dominated by volcanic activity. No guarantee that this planet would ever get anywhere...

> Most(?) humans would still be in pre-history

This is a very non-standard use of the term 'pre-history'.

Or if "they" are a thousand years ahead of us technologically then 640 years ago could be when they started building space elevators and large orbital structures.

Sure, those don't feel much like tech at our current pace of change, but it's millions of years further up the tech tree than, say, feathers, thermoregulation, photosynthesis, or multicellular organisms.